The present invention relates to valves which have an external actuator shaft connected to a valve closure element, in particular, to a tilted disc check valve having a top mounted hydraulic cylinder which is shaft connected to a tilted disc located within a body of the valve.
U.S. Pat. Nos. 4,669,500; 3,789,872; 3,942,551; and 3,785,611 all disclose a check valve which utilizes external shaft connected actuators to influence the movement of a check valve disc. Previously, in a top mounted dashpot arrangement for a check valve, if the dashpot is to be replaced or if any portion of the valve is to be repair, complete disassembly of the structure has been required. A quick replacement of a hydraulic cylinder from the other top mounted dashpot components, for repair or replacement, without having to first remove the tilted disc check valve from the pipeline is desireable.
Shaft couplings for valve applications other than check valves are known. U.S. Pat. No. 2,108,234 discloses a stem coupling for attaching adjacent ends of two stems. The mating sections of the coupling are held together by a bolt extending therethrough. U.S. Pat. No. 3,648,718 discloses an assembly for joining a valve actuator shaft with a valve stem. A connector block is used which is internally threaded and formed of two collar pieces which are bolted together and held firm by a jamb nut. U.S. Pat. No. 3,253,610 shows a connecting element having a pair of clamping jaws bolted together and having internal threads therein.
U.S. Pat. Nos. 3,353,797; 2,706,997; and 4,616,477, show coupling arrangements engaged to shafts.